Air from preserving oases



(No Model.)

J. J. HOYT.

DEVICE FOR EXHAUSTING AIR FROM PRESERVING GASES.

Patented Aug. 5, 1884. 6 -f r UNITED STATES PATENT nron.

JONATHAN J. HOYT, OF GHELMSFORD, MASSACHUSETTS, ASSIGNOR TU EDWARD F. RICHARDSON, OF SAME PLACE.

DEVICE FOR EXHAUSTING AIR FROM PRESERVING-CASES.

SPECIFICATION forming part of Letters Patent No. 303,014, dated August 5, 1884.

Application filed February 21, 1883. (Remodel) To all whom it may conccrn.-'

Be it known that I, JONATHAN J. Hora, a citizen of the United States, residing at Ghelms. ford, in the countyof Middlesex and Commonwealth of Massachusetts, have invented cer tain new and useful Improvements in Devices for EXhaust-ing Air from Cases for Preserving Food, of which the following is a specification.

My invention consists in providing the chamber with an elastic cushion. for the rising valve to strike against to prevent marring or breaking the valve or chamber; also in providing said elastic cushion with corrugations or channels, by which the air, may pass between said cushion and. the valve when the latter is raised.

In the accompanying drawings, Figure 1 is a vertical central section of a vessel or case, its cover, valve. the valve'chaniber, cuslr ion, and a pump-cylinder and piston; Fig. 2, a plan of the bottom of the cushion; Fig. 3, a vertical. section of a part of the cushion.

A is a cylindrical glass case, provided near its top with an external screw, B. On the under side of the circular cover C, also of glass,

is an annular groove, 0, in which is laid a 1 its seat being ground together to make an airtight joint.

The valve has a central manysided opening, E, in which is securely fastened a plug, E", of wood or other material, said plug being provided with a screw-thread,

bymeans of which and a screw-pointed instrument the valve may be removed.

All of the above-named parts are described in another application for patent on improvements in cases for preserving food, made by me, and now pending, and I do not claim them herein, except in combination with parts hereinafter described.

The valve-chamber H is cylindrical, and large enough to allow the valve E to rise and fall freely within it when the air within said chamber above said valve is exhausted or rarefiedby the action of a pump or other vacuuIn-producing device, and is short enough to prevent the valve from rising wholly above the projection, or from rising high enough to cant over, and thereby be prevented from falling back to its seat. This chamber H may be large enough to surround the projection 0 or may rest upon the top of said projection, being made shorter in the latter case than in the former by the distance which the projec tion (3 rises above the top of the cover G. In either case there should be an air-tight joint between the chamber and the cover when the chamber is in use. To effect this I use an annular elastic gasket, G, say of rubber, be tween the lower end of the chamber and the top of the cover. In order that thevalve may not be broken or marred, and may not break or mar the chamber when the valve is suddenly lifted by the exhaustion of air from the case A, I use an'annular elastic cushion, H, at the top of the chamber. This cushion is preferably of rubber, and is flat on its upper side, in order that it may be cemented to the top of the chamber, and thereby retained in place, and it is corrugated or channeled at h, on its lower side, as shown in Figs. 2 and 3, in order that when the valve is raised up against the cushion the air may pass between the valve and the cushion, and out at the cen tral orifice in the upper part of the chamber.

Inasmuch as the valve sometimes sticks in its seat, and because it would be difficult in some cases to detect the action of the valve by the ear, especially where a jet of steam is used to exhaust the air, owing to the noise made by the operation of the air-exhausting devices, I make the chamber of glass, so that the operator can readily see whether the valve is operating properly. The chamber has on top a tubular upward projection, H, provided at the top with a screw-thread, H A cylinder, H, also provided with a screw'thread which engages with the thread H may be screwed to the top of the tube H so as to form with said tube a continuous hollow cylinder of uniform bore. Into this hollow cylinder a piston, I, may be fitted, such piston to be provided with one or more openings, 1 I supplied with upwardly-opening valves 1 I. These valves, as shown in Fig. 1, are ordinary flap-valves. The piston is shown as being provided with a piston-rod, I and crosshead I,of the usual form, and the upper end of the cylinder is closed around the pistonrod to guide it vertically, said closed ends having passages 1 through which the airinay pass from the cylinder when the piston is lifted. It will be seen that the cylinder, the piston and its rod, and the valve-chamber, with the valve E, form a pump the lower valve of which is really a part of the ease. The thread H? on the tube also aflords a means of connecting 

